You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go up,
down or remain the same?

Most people here will get this but most "normal" people won't.

The water level in the pool goes down.
Paul K. Dickman

Tom Gardner wrote in message ...
You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go up,
down or remain the same?

Most people here will get this but most "normal" people won't.

Paul K. Dickman wrote:

Tom Gardner wrote in message ...
You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go up,
down or remain the same?

Most people here will get this but most "normal" people won't.

The water level in the pool goes down.

Unless it's a pool of mercury.

Ian Stirling wrote: Unless it's a pool of mercury.
^^^^^^^^^^^
I wouldn't eat the fish from that pool.
Since mercury is a metal, this thread is no longer OT.

On Thu, 18 Dec 2003 17:58:38 GMT, "Tom Gardner" wrote:
You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go up,
down or remain the same?

The water level goes down. That's because the boat has to displace an
amount of water equal to the weight of the concrete, while the concrete
itself only has to displace an amount of water equal to its volume. Since
concrete has a higher density than water, it displaces less water sunk
than when floated in a boat.

Gary

Naw, Gary! The concrete would cause the water level to rise so rapidly, the
resulting wave would swamp the boat causing further water level rise, which
would swamp the boat, . . . causing further water level rise, ad nauseum.
At peril to repetition of Noah's Ark incident, please don't try this
experiment!!

Bob Swinney
"Gary Coffman" wrote in message
...
On Thu, 18 Dec 2003 17:58:38 GMT, "Tom Gardner" wrote:
You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go
up,
down or remain the same?

The water level goes down. That's because the boat has to displace an
amount of water equal to the weight of the concrete, while the concrete
itself only has to displace an amount of water equal to its volume. Since
concrete has a higher density than water, it displaces less water sunk
than when floated in a boat.

Gary

You didn't specify whether or not Lacy was attached.
JR
Dweller in the cellar

Tom Gardner wrote:

You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go up,
down or remain the same?

Most people here will get this but most "normal" people won't.

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Tom Gardner wrote:

You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go
up,
down or remain the same?

Most people here will get this but most "normal" people won't.

Lets make it a little more complicated. Suppose the concrete block is
attached to the boat with a rope. When you throw it overboard, it
hangs from the boat rather than goes to the bottom of the pool.

Does the water level in the pool go up, down or remain the same?

Pete.

Peter Reilley wrote:

Tom Gardner wrote:


You're in a rowboat in a pool and there is a concrete block in the boat.
You drop the block into the water. Does the water level in the pool go


up,


down or remain the same?

Most people here will get this but most "normal" people won't.



Lets make it a little more complicated. Suppose the concrete block is
attached to the boat with a rope. When you throw it overboard, it
hangs from the boat rather than goes to the bottom of the pool.

Does the water level in the pool go up, down or remain the same?

How big is the rope?
Ken

"Ken Vale" wrote in message
.cable.rogers.com...
Peter Reilley wrote:

Tom Gardner wrote:


You're in a rowboat in a pool and there is a concrete block in the
boat.
You drop the block into the water. Does the water level in the pool go


up,


down or remain the same?

Most people here will get this but most "normal" people won't.



Lets make it a little more complicated. Suppose the concrete block is
attached to the boat with a rope. When you throw it overboard, it
hangs from the boat rather than goes to the bottom of the pool.

Does the water level in the pool go up, down or remain the same?

How big is the rope?
Ken


For this purpose, the rope is infinitely thin and weightless.

For extra credit, consider the condition where the rope has neutral
buoyancy.

Pete.

Peter Reilley wrote: For this purpose, the rope is infinitely thin and
weightless. For extra credit, consider the condition where the rope has
neutral buoyancy.
^^^^^^^^^^^^
A boat floats in the water at a depth at which it displaces its own weight
of water. The shape of the hull does not change this fact. When you tie
the concrete block to the boat, in effect you are making it part of the
boat. When you throw the block and rope into the water, you have, in
effect, changed the shape of the hull, without changing its weight, so the
amount of water displaced does not change. Therefor, the pond level does
not change. Making the rope "weightless" or of neutral buoyancy does not
make any difference. The water level does not change.